The Diabetes Control and complications Trial (DCCT) enrolled nearly 1500 subjects to answer the question whether intensive insulin treatment would prevent and/or ameliorate the early microvascular and neurologic complications of insulin-dependent diabetes mellitus. EDIC will be an epidemiologic investigation of this large cohort to continue the study of diabetic nephropathy, neuropathy and retinopathy, the development and progression of atherosclerotic cardiovascular (coronary, peripheral and cerebral) disease in these patients.